MACHINE CORE: Project Summary The onsite Machine Core is critical to the research productivity of the NEI Core Investigators and the surrounding research community. The Machine Core designs and fabricates novel research apparatuses that cannot be easily obtained by other means. The Core has evolved to have modern capabilities in computer-aided design (CAD), 5-axis fabrication, and 3D printing, as well as significant expertise in (e.g.) using 3D magnetic resonance imaging data to customize established base designs (shared by all labs) into custom designs for each lab's needs and each specific animal subject. The Machine Core acts as a physical and intellectual meeting ground to migrate apparatus design and use knowledge from one lab to another. It is very adept at detecting synergistic research needs across labs and leveraging those for efficiency and collaboration. As our very active research community frequently needs repair or modification of equipment, the Machine Core has proven critical to avoiding disruptions or delays. One cannot overstate the importance of this on-site service -- it is practically impossible for each lab to keep redundant copies of all the equipment in their lab. The Machine Core plays an important role training our principal investigators, graduate students and postdocs to gain significant ?hands-on? interaction that cannot occur remotely. These experiences inculcate researchers in computer aided design (CAD), design trade-offs (e.g. materials choices, tolerances), and the advantages and limitations of various fabrication methods, providing them confidence to try developing innovative methodologies.